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Array of Virtual Frisch-Grid CZT Detectors with Common Cathode Readout for Correcting Charge Trapping and Rejecting Incomplete Charge Collection
N/A
Date:
April 9, 2013
Creator:
A., Bolotnikov
Object Type:
Article
System:
The UNT Digital Library
Projections of potential luminosity improvement for low-energy RHIC operation with electron cooling
N/A
Date:
April 1, 2013
Creator:
A., Fedotov
Object Type:
Report
System:
The UNT Digital Library
A Rosetta Stone Relating Conventions In Photo-Meson Partial Wave Analyses
A new generation of complete experiments in pseudoscalar meson photo-production is being pursued at several laboratories. While new data are emerging, there is some confusion regarding definitions of asymmetries and the conventions used in partial wave analyses (PWA). We present expressions for constructing asymmetries as coordinate-system independent ratios of cross sections, along with the names used for these ratios by different PWA groups.
Date:
April 1, 2012
Creator:
A.M. Sandorfi, B. Dey, A. Sarantsev, L. Tiator, R. Workman
Object Type:
Article
System:
The UNT Digital Library
Images of Quark Intrinsic Motion in Covariant Parton Model
We discuss the relations between TMDs and PDFs in the framework of the covariant parton model. The quark OAM and its connection to TMDs are studied as well.
Date:
April 1, 2010
Creator:
A.V. Efremov, P. Schweitzer, O.V. Teryaev, P. Zavada
Object Type:
Article
System:
The UNT Digital Library
EVALUATION OF TEMPORAL VARIATIONS IN HYDRAULIC CAPTURE DUE TO CHANGING FLOW PATTERNS USING MAPPING AND MODELING TECHNIQUES
Robust performance evaluation represents one of the most challenging aspects of groundwater pump-and-treat (P&T) remedy implementation. In most cases, the primary goal of the P&T system is hydraulic containment, and ultimately recovery, of contaminants to protect downgradient receptors. Estimating the extent of hydraulic containment is particularly challenging under changing flow patterns due to variable pumping, boundaries and/or other conditions. We present a systematic approach to estimate hydraulic containment using multiple lines of evidence based on (a) water-level mapping and (b) groundwater modeling. Capture Frequency Maps (CFMs) are developed by particle tracking on water-level maps developed for each available water level data set using universal kriging. In a similar manner, Capture Efficiency Maps (CEMs) are developed by particle tracking on water-levels calculated using a transient groundwater flow model: tracking is undertaken independently for each stress period using a very low effective porosity, depicting the 'instantaneous' fate of each particle each stress period. Although conceptually similar, the two methods differ in their underlying assumptions and their limitations: their use together identifies areas where containment may be reliable (i.e., where the methods are in agreement) and where containment is uncertain (typically, where the methods disagree). A field-scale example is presented to illustrate these …
Date:
April 7, 2011
Creator:
AA, SPILIOTOPOULOS; LC, SWANSON; R, SHANNON & MJ, TONKIN
Object Type:
Article
System:
The UNT Digital Library
INTERIM REPORT--INDEPENDENT VERIFICATION SURVEY OF SECTION 3, SURVEY UNITS 1, 4 AND 5 EXCAVATED SURFACES, WHITTAKER CORPORATION, REYNOLDS INDUSTRIAL PARK, TRANSFER, PENNSYLVANIA DCN: 5002-SR-04-0"
At Pennsylvania Department of Environmental Protection's request, ORAU's IEAV program conducted verification surveys on the excavated surfaces of Section 3, SUs 1, 4, and 5 at the Whittaker site on March 13 and 14, 2013. The survey activities included visual inspections, gamma radiation surface scans, gamma activity measurements, and soil sampling activities. Verification activities also included the review and assessment of the licensee�s project documentation and methodologies. Surface scans identified four areas of elevated direct gamma radiation distinguishable from background; one area within SUs 1 and 4 and two areas within SU5. One area within SU5 was remediated by removing a golf ball size piece of slag while ORAU staff was onsite. With the exception of the golf ball size piece of slag within SU5, a review of the ESL Section 3 EXS data packages for SUs 1, 4, and 5 indicated that these locations of elevated gamma radiation were also identified by the ESL gamma scans and that ESL personnel performed additional investigations and soil sampling within these areas. The investigative results indicated that the areas met the release criteria.
Date:
April 18, 2013
Creator:
ADAMS, WADE C
Object Type:
Report
System:
The UNT Digital Library
CONFIRMATORY SURVEY OF THE FUEL OIL TANK AREA HUMBOLDT BAY POWER PLANT EUREKA, CALIFORNIA
During the period of February 14 to 15, 2012, ORISE performed radiological confirmatory survey activities for the former Fuel Oil Tank Area (FOTA) and additional radiological surveys of portions of the Humboldt Bay Power Plant site in Eureka, California. The radiological survey results demonstrate that residual surface soil contamination was not present significantly above background levels within the FOTA. Therefore, it is ORISE’s opinion that the radiological conditions for the FOTA surveyed by ORISE are commensurate with the site release criteria for final status surveys as specified in PG&E’s Characterization Survey Planning Worksheet. In addition, the confirmatory results indicated that the ORISE FOTA survey unit Cs-137 mean concentrations results compared favorably with the PG&E FOTA Cs-137 mean concentration results, as determined by ORISE from the PG&E characterization data. The interlaboratory comparison analyses of the three soil samples analyzed by PG&E’s onsite laboratory and the ORISE laboratory indicated good agreement for the sample results and provided confidence in the PG&E analytical procedures and final status survey soil sample data reporting.
Date:
April 9, 2012
Creator:
ADAMS, WADE C.
Object Type:
Report
System:
The UNT Digital Library
Clean Air Status and Trends Network Annual Report: 2010
Annual report of the Clean Air Status and Trends Network (CASTNET) describing the program and data collection. It also presents information on air quality and recorded concentrations of pollutants such as ozone, sulfur, gases, and other elements of concern.
Date:
April 2012
Creator:
AMEC Environment & Infrastructure, Inc.
Object Type:
Report
System:
The UNT Digital Library
Clean Air Status and Trends Network Annual Report: 2012
Annual report of the Clean Air Status and Trends Network (CASTNET) describing the program and data collection. It also presents information on air quality and recorded concentrations of pollutants such as ozone, sulfur, gases, and other elements of concern.
Date:
April 2014
Creator:
AMEC Environment & Infrastructure, Inc.
Object Type:
Report
System:
The UNT Digital Library
Jet Mass and Substructure of Inclusive Jets in $\sqrt{s}=7$ TeV $Pp$ Collisions with the ATLAS Experiment
None
Date:
April 2, 2013
Creator:
Aad, Georges
Object Type:
Article
System:
The UNT Digital Library
Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays
This report talks about Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays
Date:
April 20, 2012
Creator:
Aaltonen, T
Object Type:
Article
System:
The UNT Digital Library
Measurement of Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV
The production rate and kinematics of photons produced in association with Z bosons are studied using 2 fb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross section for p{bar p} {yields} {ell}{sup +}{ell}{sup -}{gamma} + X (where the leptons {ell} are either muons or electrons with dilepton mass M{sub {ell}{ell}} > 40 GeV/c{sup 2}, and where the photon has transverse energy E{sub T}{sup {gamma}} > 7 GeV and is well separated from the leptons) is 4.6 {+-} 0.2 (stat) {+-} 0.3 (syst) {+-} 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon ET distribution from Z{gamma} events where the Z has decayed to {mu}{sup +}{mu}{sup -}, e{sup +}e{sup -}, or {nu}{bar {nu}} to set limits on anomalous (non-standard-model) trilinear couplings between photons and Z bosons.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Observation of Single Top Quark Production and Measurement of |Vtb| with CDF
We report the observation of electroweak single top quark production in 3.2 fb{sup -1} of p{bar p} collision data collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events in the W+jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3{sub -0.5}{sup +0.6}(stat + sys) pb, extract the CKM matrix element value |V{sub tb}| = 0.91{sub -0.11}{sup +0.11}(stat + sys) {+-} 0.07(theory), and set a lower limit |V{sub tb}| > 0.71 at the 95% confidence level, assuming m{sub t} = 175 GeV/c{sup 2}.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for New Bottomlike Quark Pair Decays Q Q-Bar to (T W- ) (T-Bar W -) in Same-Charge Dilepton Events
We report the most restrictive direct limits on masses of fourth-generation down-type quarks b{prime}, and quark-like composite fermions (B or T{sub 5/3}), decaying promptly to tW{sup {-+}}. We search for a significant excess of events with two same-charge leptons (e, {mu}), several hadronic jets, and missing transverse energy. An analysis of data from p{bar p} collisions with an integrated luminosity of 2.7 fb{sup -1} collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits m{sub b{prime}}, m{sub B} > 338 GeV/c{sup 2} and m{sub T{sub 5/3}} > 365 GeV/c{sup 2} at 95% confidence level.
Date:
April 2, 2012
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of $B_s^0 \to D_s^{(*)+} D_s^{(*)-}$ Branching Ratios
The decays B{sub s}{sup 0} {yields} D{sub s}{sup (*)+}D{sub s}{sup (*)-}s are reconstructed in a data sample corresponding to an integrated luminosity of 6.8 fb{sup -1} collected by the CDF II detector at the Tevatron p{bar p} collider. All decay modes are observed with a significance of more than 10 {sigma}, and we measure the B{sub s}{sup 0} production rate times B{sub s}{sup 0} {yields} D{sub s}{sup (*)+} D{sub s}{sup (*)-} branching ratios relative to the normalization mode B{sup 0} {yields} D{sub s}{sup +}d{sup -} to be 0.183 {+-} 0.021 {+-} 0.017 for B{sub s}{sup 0} {yields} D{sub s}{sup +}D{sub s}{sup -}, 0.424 {+-} 0.046 {+-} 0.035 for B{sub s}{sup 0} {yields} D{sub s}{sup {+-}} D{sub s}{sup {-+}}, 0.654 {+-} 0.072 {+-} 0.065 for B{sub s}{sup 0} {yields} D{sub s}{sup *+} D{sub s}{sup *-}, and 1.261 {+-} 0.095 {+-} 0.112 for the inclusive decay B{sub s}{sup 0} {yields} D{sub s}{sup (*)+}D{sub s}{sup (*)-}, where the uncertainties are statistical and systematic. These results are the most precise single measurements to date and provide important constraints for indirect searches for non-standard model physics in B{sub s}{sup 0} mixing.
Date:
April 1, 2012
Creator:
Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type:
Article
System:
The UNT Digital Library
First Measurement of the Ratio sigma_(t-tbar) / sigma_(Z/\gamma*->ll) and Precise Extraction of the t-tbar Cross Section
We report a measurement of the ratio of the t{bar t} to Z/{gamma}* production cross sections in {radical}s = 1.96 TeV p{bar p} collisions using data corresponding to an integrated luminosity of up to 4.6 fb{sup -1}, collected by the CDF II detector. The t{bar t} cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/{gamma}* {yields} ll cross section predicted by the standard model, the extracted t{bar t} cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result {sigma}{sub t{bar t}} = 7.70 {+-} 0.52 pb, for a top-quark mass of 172.5 GeV/c{sup 2}.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction
The collection of a large number of B hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper decay time distribution. A lifetime measurement must correct for this bias and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper they present an analytic method for bias correction without using simulation, thereby removing any uncertainty between data and simulation. This method is presented in the form of a measurement of the lifetime of the B{sup -} using the mode B{sup -} {yields} D{sup 0}{pi}{sup -}. The B{sup -} lifetime is measured as {tau}{sub B{sup -}} = 1.663 {+-} 0.023 {+-} 0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type:
Article
System:
The UNT Digital Library
Search for the Rare Radiative Decay: $W\rightarrow\pi\gamma$ in $p\bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV
We present a search for the rare radiative decay W{sup {+-}} {yields} {pi}{sup {+-}}{gamma} using data corresponding to an integrated luminosity of 4.3 fb{sup -1} of proton-antiproton collisions at a center of mass energy of 1.96 TeV collected by the CDF experiment at Fermilab. As no statistically significant signal is observed, we set a 95% confidence level upper limit on the relative branching fraction {Gamma}(W{sup {+-}} {yields} {pi}{sup {+-}}{gamma})/{Gamma}(W{sup {+-}} {yields} e{sup {+-}}{nu}) at 6.4 x 10{sup -5}, a factor of 10 improvement over the previous limit.
Date:
April 1, 2011
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Oviedo U. /Cantabria Inst. of; Amerio, S.; /INFN, Padua et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the $\Lambda_b^0$ lifetime in the exclusive decay $\Lambda_b^0 \to J/\psi \Lambda^0$ in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
We measure the {Lambda}{sub b}{sup 0} lifetime in the fully reconstructed decay {Lambda}{sub b}{sup 0} {yields} J/{psi} {Lambda}{sup 0} using 10.4 fb{sup -1} of p{bar p} collisions collected with the D0 detector at {radical}s = 1.96 TeV. The lifetime of the topologically similar decay channel B{sup 0} {yields} J/{psi} K{sub S}{sup 0} is also measured. We obtain {tau} ({Lambda}{sub b}{sup 0}) = 1.303 {+-} 0.075 (stat.) {+-} 0.035 (syst.) ps and {tau} (B{sup 0}) = 1.508 {+-} 0.025 (stat.) {+-} 0.043 (syst.) ps. Using these measurements, we determine the lifetime ratio of {tau} ({Lambda}{sub b}{sup 0})/{tau} (B{sup 0}) = 0.864 {+-} 0.052 (stat.) {+-} 0.033 (syst.).
Date:
April 1, 2012
Creator:
Abazov, Victor Mukhamedovich & al., et
Object Type:
Article
System:
The UNT Digital Library
Search for Randall-Sundrum gravitons in the dielectron and diphoton final states with 5.4fb$^{-1}$ of data from $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
Using 5.4 fb{sup -1} of integrated luminosity from p{bar p} collisions at {radical}s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider, we search for decays of the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model to ee and {gamma}{gamma}. We set 95% C.L. lower limits on the mass of the lightest graviton between 560 GeV and 1050 GeV for values of the coupling k/{bar M}{sub Pl} between 0.01 and 0.1.
Date:
April 1, 2010
Creator:
Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; U., /Oklahoma; Abolins, Maris A.; U., /Michigan State et al.
Object Type:
Article
System:
The UNT Digital Library
LEEM investigations of clean surfaces driven by energetic ion beams
The original purpose of this award was to use low‐energy electron microscopy (LEEM) to explore the dynamics of surfaces of clean single crystal surfaces when driven by a beam of energetic ions. The goal was to understand the nanoscience of hyperthermal growth, surface erosion by sublimation and irradiation, operation of surface sinks in irradiated materials, diffusion on driven surfaces, and the creation of structural patterns. This project was based on a novel LEEM system constructed by C. P. Flynn, which provided real‐time imaging of surface dynamics by scattering low energy electrons. With the passing of Prof. Flynn in late 2011, this project was completed under a slightly different scope by constructing a low‐energy, inelastic electron scattering (�EELS�) instrument. Consistent with Flynn�s original objectives for his LEEM system, this device probes the dynamics of crystal surfaces. However the measurements are not carried out in real time, but instead are done in the frequency domain, through the energy lost from the probe electrons. The purpose of this device is to study the collective bosonic excitations in a variety of materials, including high temperature superconductors, topological insulators, carbon allotropes including (but not limited to) graphene, etc. The ultimate goal here is to identify …
Date:
April 24, 2013
Creator:
Abbamonte, Peter M.
Object Type:
Report
System:
The UNT Digital Library
Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes
The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.
Date:
April 11, 2012
Creator:
Abdo, A. A.; Ackermann, M.; Ajello, M.; Anderson, B.; Atwood, W. B.; Axelsson, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Fermi LAT Observations of LS I +61 303: First Detection of an Orbital Modulation in GeV Gamma Rays
This Letter presents the first results from the observations of LS I +61{sup o}303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 {+-} 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 {+-} 0.03(stat) {+-} 0.07(syst) 10{sup -6} ph cm{sup -2} s{sup -1}, with a cutoff at 6.3 {+-} 1.1(stat) {+-} 0.4(syst) GeV and photon index {Gamma} = 2.21 {+-} 0.04(stat) {+-} 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest that the link …
Date:
April 2, 2012
Creator:
Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Axelsson, M.; Baldini, L. et al.
Object Type:
Article
System:
The UNT Digital Library
Abraham Lincoln Bicentennial Commission: Final Report to Congress and the American People
Final report of the Abraham Lincoln Bicentennial Commission describing its activities commemorating the 200th birthday of America's 16th president.
Date:
April 2010
Creator:
Abraham Lincoln Bicentennial Commission
Object Type:
Report
System:
The UNT Digital Library